I'm surprised that no one has talked about landing near the newly discovered Martian blackholes or possibly the guyser at the pole (although they may be too dangerous). At the very least, MSL should land somewhere that is not favorable to solar powered rovers.

Considering the moderately persuasive argument supporting the notion of a past ocean in the northern hemisphere, as reported in the current issue of Nature (http://www.nature.com.libux.utmb.edu/nature/journal/v447/n7146/full/nature05873.html - if you have access), I would be inclined to shift my preference to a landing site which would be near exposed sediments from the floor of that ocean, perhaps in delta deposits. To me, the odds are that if any macroscopic life ever evolved on Mars, it would have been in this ocean, and sedimentary deposits from the bottom of the ocean would be the best places to look for fossils, as well as a sedimentary sequence which tells an interesting story. I'm not sure whether there would be any benefit to traversing the remnant shoreline itself.

I'm having trouble matching landing site candidates with the map in the paper, but Nilo Syrtis and Marwth Vallis might be good.

I hope I'm not appearing to be super-pedantic here; it's just that this is a very common spelling mistake (looks like it derives from a MEX OMEGA Science paper, and some related press releases where they got it wrong.).

If you're wondering about the pronunciation, it's similar to "Martha" without the second "a"!

The more pounds per square foot (grams per square centimeter) of vehicle you have behind a heatshield (and a bigger vehicle is more or less inevitably deeper, front to back with more "column mass"), the less the atmosphere can slow you down before you do "ares-braking" instead of "aero-braking"...

zip..... CRUNCH!

I'm going to be off by a factor of a few times, but here's a zero'h order armwave...

Mars. 1/200'th atmosphere surface pressure. That's about 10 ounces / 30 grams per square inch. Double that (roughly) to compensate for gravity. How many ounces per square inch is the MSL in it's heat shield? There's only so many pounds of atmosphere in the way of a so many pound entry vehicle trying to slow it down.

When an entry vehicle masses more than a column of atmosphere of the same diameter between surface and space, it just can't slow down a vehicle before the vehicle hits. Would a column of atmosphere (along an entry trajectory) massing the same as an entry vehicle slow it down 50%... very very roughly, I think so (ignoring gravity).

After looking at all the MRO landing site images and counting rocks and such, it just makes sense to this complete amateur that the only place to set down MSL is on/near the famous ice packs of Elysium Planatia.

water? / ice? / extant life?

What would I add to the mission?...bring an industrial sized RAT and BRUSH

Elysium Planitia (AKA ice pack) might look like a good landing site, but there are some problems with it. First, it might be classed as a "special region", which MSL will not be sufficiently sterilized to land in. In the event of a crash, the RTG could encounter ice and create a warm water oasis (not very big, certainly, but still viable). This is not allowed for MSL. (Phoenix should encounter ice, but it will remain very cold).

Second, MSL's instruments don't suit it. A drill might be needed to get to any ice. This could be an ideal spot for a thoroughly sterilized deep drill mission in the future.

Also, Elysium Planitia is really a one target site. Once you have looked at one location, what is there to do? It's quite uniform. MSL is designed to explore up and down a stack of sediments, or a similar multi-target site. For this reason, MSL would also be wasted on one of the 'windows' mentioned in a post above.

An ideal MSL site will have dozens of distinct targets within about 10 or 15 km of the landing site, plus a potential for a really good extended mission with many more targets over a much longer traverse.

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QUOTE (Phil Stooke @ Jul 13 2007, 05:53 PM)

Elysium Planitia (AKA ice pack) might look like a good landing site, but there are some problems with it. First, it might be classed as a "special region", which MSL will not be sufficiently sterilized to land in.

Can somebody explain me why some part of Phoenix are sterilized at 300.000 spore/m² while the arm is at 1 spore/m² (source Phoenix-Launch-presskit)? I mean, why can we sterilize MSL with the later value at least for the parts in contact with Mars ?

PS : not only there is a risk of crash for MSL RTG's but also the Crane (or whaterver you call it) will definitively crash anyway.

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